5.11 PACKAGE

A package is a group of procedures and functions managed as one entity.

5.11.1 CREATE PACKAGE

Used forDeclaring the package header

Available inDSQL

Syntax

CREATE PACKAGE package_name
[SQL SECURITY {INVOKER | DEFINER}]
AS
BEGIN
  [ <package_item> ... ]
END
 
<package_item> ::=
    <function_decl>;
  | <procedure_decl>;
 
<function_decl> ::=
  FUNCTION funcname [ ( [ <in_params> ] ) ]
  RETURNS <domain_or_non_array_type> [COLLATE collation]
  [DETERMINISTIC]
 
<procedure_decl> ::=
  PROCEDURE procname [ ( [ <in_params> ] ) ]
  [RETURNS (<out_params>)]
 
<in_params> ::= <inparam> [, <inparam> ... ]
 
<inparam> ::= <param_decl> [ { = | DEFAULT } <value> ]
 
<out_params> ::= <outparam> [, <outparam> ...]
 
<outparam> ::= <param_decl>
 
<value> ::= { literal | NULL | context_var }
 
<param-decl> ::= paramname <domain_or_non_array_type> [NOT NULL]
  [COLLATE collation]
 
<domain_or_non_array_type> ::=
  !! See Scalar Data Types Syntax !!

Table 5.11.1.1 CREATE PACKAGE Statement Parameters

The CREATE PACKAGE statement creates a new package header. Routines (procedures and functions) declared in the package header are available outside the package using the full identifier (package_name.proc_name or package_name.func_name). Routines defined only in the package body — but not in the package header — are not visible outside the package.

Package procedure and function names may shadow global routines

If a package header or package body declares a procedure or function with the same name as a stored procedure or function in the global namespace, it is not possible to call that global procedure or function from the package body. In this case, the procedure or function of the package will always be called.

For this reason, it is recommended that the names of stored procedures and functions in packages do not overlap with names of stored procedures and functions in the global namespace.

5.11.1.1 Statement Terminators

Some SQL statement editors — specifically the isql utility that comes with Firebird and possibly some third-party editors — employ an internal convention that requires all statements to be terminated with a semi-colon. This creates a conflict with PSQL syntax when coding in these environments. If you are unacquainted with this problem and its solution, please study the details in the PSQL chapter in the section entitled Switching the Terminator in isql.

5.11.1.2 SQL Security

The SQL SECURITY clause specifies the security context for executing other routines or inserting into other tables from functions or procedures defined in this package. When SQL Security is not specified, the default value of the database is applied at runtime.

The SQL SECURITY clause can only be specified for the package, not for individual procedures and functions of the package.

See also SQL Security in chapter Security.

5.11.1.3 Procedure and Function Parameters

For details on stored procedure parameters, see Section 5.8.1.2, Parameters in Section 5.8.1, CREATE PROCEDURE.

For details on function parameters, see Section 5.9.1.2, Parameters in Section 5.9.1, CREATE FUNCTION.

5.11.1.4 Who Can Create a Package

The CREATE PACKAGE statement can be executed by:

• Administrators

• Users with the CREATE PACKAGE privilege

The user who created the package header becomes its owner.

5.11.1.5 Examples of CREATE PACKAGE

1. Create a package header

CREATE PACKAGE APP_VAR
AS
BEGIN
  FUNCTION GET_DATEBEGIN() RETURNS DATE DETERMINISTIC;
  FUNCTION GET_DATEEND() RETURNS DATE DETERMINISTIC;
  PROCEDURE SET_DATERANGE(ADATEBEGIN DATE,
      ADATEEND DATE DEFAULT CURRENT_DATE);
END

1. With DEFINER set for package pk, user US needs only the EXECUTE privilege on pk. If it were set for INVOKER, either the user or the package would also need the INSERT privilege on table t.

   create table t (i integer);
   set term ^;
   create package pk SQL SECURITY DEFINER
   as
   begin
       function f(i integer) returns int;
   end^
    
   create package body pk
   as
   begin
       function f(i integer) returns int
       as
       begin
         insert into t values (:i);
         return i + 1;
       end
   end^
   set term ;^
   grant execute on package pk to user us;
    
   commit;
    
   connect 'localhost:/tmp/69.fdb' user us password 'pas';
   select pk.f(3) from rdb$database;

See alsoCREATE PACKAGE BODY, RECREATE PACKAGE BODY, Section 5.11.2, ALTER PACKAGE, Section 5.11.4, DROP PACKAGE, Section 5.11.5, RECREATE PACKAGE

5.11.2 ALTER PACKAGE

Used forAltering the package header

Available inDSQL

Syntax

ALTER PACKAGE package_name
[SQL SECURITY {INVOKER | DEFINER}]
AS
BEGIN
  [ <package_item> ... ]
END
 
!! See syntax of CREATE PACKAGE for further rules!!

The ALTER PACKAGE statement modifies the package header. It can be used to change the number and definition of procedures and functions, including their input and output parameters. However, the source and compiled form of the package body is retained, though the body might be incompatible after the change to the package header. The validity of a package body for the defined header is stored in the column RDB$PACKAGES.RDB$VALID_BODY_FLAG.

Altering a package without specifying the SQL SECURITY clause will remove the SQL Security property if currently set for this package. This means the behaviour will revert to the database default.

5.11.2.1 Who Can Alter a Package

The ALTER PACKAGE statement can be executed by:

• Administrators

• The owner of the package

• Users with the ALTER ANY PACKAGE privilege

5.11.2.2 Examples of ALTER PACKAGE

Modifying a package header

ALTER PACKAGE APP_VAR
AS
BEGIN
  FUNCTION GET_DATEBEGIN() RETURNS DATE DETERMINISTIC;
  FUNCTION GET_DATEEND() RETURNS DATE DETERMINISTIC;
  PROCEDURE SET_DATERANGE(ADATEBEGIN DATE,
      ADATEEND DATE DEFAULT CURRENT_DATE);
END

See alsoSection 5.11.1, CREATE PACKAGE, Section 5.11.4, DROP PACKAGE, ALTER PACKAGE BODY, RECREATE PACKAGE BODY

5.11.3 CREATE OR ALTER PACKAGE

Used forCreating a new or altering an existing package header

Available inDSQL

Syntax

CREATE OR ALTER PACKAGE package_name
[SQL SECURITY {INVOKER | DEFINER}]
AS
BEGIN
  [ <package_item> ... ]
END
 
!! See syntax of CREATE PACKAGE for further rules!!

The CREATE OR ALTER PACKAGE statement creates a new package or modifies an existing package header. If the package header does not exist, it will be created using CREATE PACKAGE. If it already exists, then it will be modified using ALTER PACKAGE while retaining existing privileges and dependencies.

5.11.3.1 Examples of CREATE OR ALTER PACKAGE

Creating a new or modifying an existing package header

CREATE OR ALTER PACKAGE APP_VAR
AS
BEGIN
  FUNCTION GET_DATEBEGIN() RETURNS DATE DETERMINISTIC;
  FUNCTION GET_DATEEND() RETURNS DATE DETERMINISTIC;
  PROCEDURE SET_DATERANGE(ADATEBEGIN DATE,
      ADATEEND DATE DEFAULT CURRENT_DATE);
END

See alsoSection 5.11.1, CREATE PACKAGE, Section 5.11.2, ALTER PACKAGE, Section 5.11.5, RECREATE PACKAGE, ALTER PACKAGE BODY, RECREATE PACKAGE BODY

5.11.4 DROP PACKAGE

Used forDropping a package header

Available inDSQL

Syntax

DROP PACKAGE package_name

Table 5.11.4.1 DROP PACKAGE Statement Parameters

The DROP PACKAGE statement deletes an existing package header. If a package body exists, it will be dropped together with the package header. If there are still dependencies on the package, an error will be raised.

5.11.4.1 Who Can Drop a Package

The DROP PACKAGE statement can be executed by:

• Administrators

• The owner of the package

• Users with the DROP ANY PACKAGE privilege

5.11.4.2 Examples of DROP PACKAGE

Dropping a package header

DROP PACKAGE APP_VAR

See alsoSection 5.11.1, CREATE PACKAGE, DROP PACKAGE BODY

5.11.5 RECREATE PACKAGE

Used forCreating a new or recreating an existing package header

Available inDSQL

Syntax

RECREATE PACKAGE package_name
[SQL SECURITY {INVOKER | DEFINER}]
AS
BEGIN
  [ <package_item> ... ]
END
 
!! See syntax of CREATE PACKAGE for further rules!!

The RECREATE PACKAGE statement creates a new package or recreates an existing package header. If a package header with the same name already exists, then this statement will first drop it and then create a new package header. It is not possible to recreate the package header if there are still dependencies on the existing package, or if the body of the package exists. Existing privileges of the package itself are not preserved, nor are privileges to execute the procedures or functions of the package.

5.11.5.1 Examples of RECREATE PACKAGE

Creating a new or recreating an existing package header

RECREATE PACKAGE APP_VAR
AS
BEGIN
  FUNCTION GET_DATEBEGIN() RETURNS DATE DETERMINISTIC;
  FUNCTION GET_DATEEND() RETURNS DATE DETERMINISTIC;
  PROCEDURE SET_DATERANGE(ADATEBEGIN DATE,
      ADATEEND DATE DEFAULT CURRENT_DATE);
END

See alsoSection 5.11.1, CREATE PACKAGE, Section 5.11.4, DROP PACKAGE, CREATE PACKAGE BODY, RECREATE PACKAGE BODY